The diagram below depicts the architecture with its components.
The WSO2 CEP architecture consists of the following components:
Event receivers receive events that are coming to the CEP. WSO2 CEP supports the most common adapter implementations by default. For specific use cases, you can also plug custom adapters. For more information, see Configuring Event Receivers.
Event streams contain unique sets of attributes of specific types that provide a structure based on which the events processed by the relevant event flow are selected. Event streams are stored as stream definitions in the file system via the data bridge stream definition store.
Event processor handles actual event processing. It is the core event processing unit of the CEP. It manages different execution plans and processes events based on logic, with the help of different Siddhi queries. Event Processor gets a set of event streams from the Event Stream Manager, processes them using Siddhi engine, and triggers new events on different event streams back to the Event Stream Manager. For more information, see Creating a Standalone Execution Plan.
Event publishers publish events to external systems and store data to databases for future analysis. Like the event receivers, this component also has different adapter implementations. The most common ones are available by default in the CEP. You can implement custom adapters for specific use cases. For more information, see Configuring CEP to Create Alerts.